1. Field of the Invention
The present invention relates to a flat-type fluorescent lamp and a liquid crystal display (“LCD”) and, more particularly, to a flat-type fluorescent lamp minimizing pin-holes therein and an LCD having the flat-type fluorescent lamp.
2. Description of the Related Art
A liquid crystal display (“LCD”) displays images by passing light through liquid crystal molecules that have optical birefringence characteristics. The LCD is lighter, thinner, and more power-effective than other display devices such as a cathode ray tube (“CRT”) and a plasma display panel (“PDP”).
Because the LCD is not a self-emissive display, the LCD needs a light source at the rear side of the LCD. Conventionally, as a light source, the narrow and thin cold cathode fluorescent lamp (“CCFL”) has been used. However, the number of CCFLs per LCD increases as the size of the LCD increases, thereby heightening manufacturing cost and luminance irregularity.
To lower the manufacturing cost and enhance luminance uniformity, the flat-type fluorescent lamp, which emits light from a wider surface than the conventional CCFL, has been suggested. The flat-type fluorescent lamp includes a lamp body having a number of separate discharging spaces and a pair of external electrodes providing electricity to the discharging spaces of the lamp body. The lamp body has a pair of glass substrates, at least one of which is structured so as to form the discharging spaces. The lamp body also includes a fluorescent layer within the discharging spaces for radiating light.
By supplying electricity to the external electrodes from a power source such as an inverter, plasma and ultra violet rays are sequentially generated in each of the discharging spaces, thereafter, visible rays are radiated as the ultra violet rays pass through the fluorescent layer.
In supplying electricity, if either an excessive voltage greater than an insulation destructing voltage or an excessive current greater than a critical current is supplied to the external electrodes, the lamp body could be damaged at a location covered by the external electrodes. Even worse, the Joule heat may melt the lamp body and produce pin-holes on the external electrodes or the glass substrate. Afterwards, through the pin-holes, plasma gas, such as neon Ne, helium He, argon Ar, or mercury Hg gas, in the discharging spaces could leak out to an exterior of the lamp body. Also, outer gas may flow into the discharging spaces through the pin-holes. As a result, the flat-type fluorescent lamp is driven abnormally causing irregular radiation or even radiation failure.
Accordingly, there has been a need for a flat-type fluorescent lamp and LCD to be driven normally and stably by minimizing the pin-holes.